To provide a manufacturing method of a photocurable sealant having high moisture permeability resistance and exhibiting excellent performance in sealing of an electronic component case.

The photocurable sealant is prepared by mixing (A) one or more bifunctional (meth)acrylate having (meth)acryloyl groups at both terminals of an aliphatic hydrocarbon, which has a 3-15C main chain and may have a branched chain, (B) one or more monofunctional (meth)acrylate having a (meth)acryloyl group at one terminal of 6-20C chain alkyl skeleton which may have a branched chain, (C) a styrene-isobutylene block copolymer, (D) a photopolymerization initiator, and (E) silica powder together. When the photocurable sealant is applied onto a member and irradiated with light, the member such as the electronic component case having a sealing layer is obtained.